The present application relates to the use of 3-(2,4,6-trimethylphenyl)-4-neopentylcarbonyloxy-5,5-tetramethylene-xcex943-dihydrofuaran-2-one for controlling insects of the family Aleurodidae (white fly).
The compound 3-(2,4,6-trimethylphenyl)-4-neopentylcarbonyloxy-5,5-tetramethylene-xcex943-dihydrofuaran-2-one is known from EP-A-0 528 156.
Furthermore, EP-A-0 528 156 discloses that 3-(2,4,6-trimethylphenyl)-4-neopentylcarbonyloxy-5,5-tetramethylene-xcex943-dihydrofuran-2-one has insecticidal action.
Surprisingly, it has now been found that 3-(2,4,6-trimethylphenyl)-4-neopentyl-carbonyloxy-5,5-tetramethylene-A3-dihydrofuran-2-one is particularly suitable for controlling insects of the family Aleurodidae (white fly) and additionally has considerably better action than the constitutionally most similar compounds known from EP-A-0 528 156.
The present invention accordingly relates to the use of 3-(2,4,6-trimethylphenyl)-4-neopentylcarbonyloxy-5,5-tetramethylene-xcex943-dihydrofuaran-2-one for controlling insects of the family of the Aleurodidae (white fly).
3-(2,4,6-Trimethylphenyl)-4-neopentylcarbonyloxy-5,5-tetramethylene-xcex943-dihydrofuran-2-one has the following formula (I): 
The compound of the formula (I) can preferably be employed for controlling insects of the genera Bemisia, Trialeurodes, Aleurotrixus, Allurodes, Dialeurodes and Aleurocanthus. The following species may be mentioned by way of example: Trialeurodes vaporariorum, Bemisia tabaci, Aleurotrixus floccosus and Aleurodes brassicae. 
In principle, the compound of the formula (I) can be used in a large number of crops, preferably in cotton, vegetables (for example tomato, aubergines, beans, cucumbers, courgettes, capsicum, melons), ornamental plants, tobacco and citrus plants.
The active compound of the formula (I) can be converted into the customary formulations, such as solutions, emulsions, wettable powders, suspensions, powders, dusts, pastes, soluble powders, granules, suspoemulsion concentrates, natural and synthetic materials impregnated with active compound, and very fine capsules in polymeric substances.
These formulations are produced in a known manner, for example by mixing the active compound with extenders, that is liquid solvents and/or solid carriers, optionally with the use of surfactants, that is emulsifiers and/or dispersants and/or foam-formers.
If the extender used is water, it is also possible to employ for example organic solvents as auxiliary solvents. Suitable liquid solvents are essentially: aromatics, such as xylene, toluene or alkylnaphthalenes, chlorinated aromatics and chlorinated aliphatic hydrocarbons, such as chlorobenzenes, chloroethylenes or methylene chloride, aliphatic hydrocarbons, such as cyclohexane, or paraffins, for example mineral oil fractions, mineral and vegetable oils, alcohols, such as butanol or glycol, and also their ethers and esters, ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents, such as dimethylformamide and dimethyl sulphoxide, and also water.
Suitable solid carriers are: for example ammonium salts and ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, and ground synthetic minerals such as finely divided silica, alumina and silicates; suitable solid carriers for granules are: for example crushed and fractionated natural rocks such as calcite, marble, pumice, sepiolite and dolomite, and also synthetic granules of inorganic and organic meals, and granules of organic material such as sawdust, coconut shells, maize crops and tobacco stalks; suitable emulsifiers and/or foam-formers are: for example nonionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, for example alkylaryl poly-glycol ethers, alkylsulphonates, alkyl sulphates, arylsulphonates and also protein hydrolysates; suitable dispersants are: for example lignin-sulphite waste liquors and methylcellulose.
Adhesives such as carboxymethylcellulose and natural and synthetic polymers in the form of powders, granules or latices, such as gum arabic, polyvinyl alcohol and polyvinyl acetate, and also natural phospholipids, such as cephalins and lecithins, and synthetic phospholipids, can be used in the formulations. Other possible additives are mineral and vegetable oils.
It is possible to use colorants such as inorganic pigments, for example iron oxide, titanium oxide and Prussian Blue, and organic dyestuffs, such as alizarin dyestuffs, azo dyestuffs and metal phthalocyanine dyestuffs, and trace nutrients such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc,
The formulations in general contain between 0.1 and 95% by weight of active compound, preferably between 0.5 and 90%, and additionally preferably extenders and/or surfactants.
The active compound content of the use forms prepared from the commercial formulations can be varied within wide ranges. The concentration of active compound in the use forms can be from 0.0000001 to 95% by weight of active compound, and is preferably between 0.0001 and 1% by weight.
Application is carried out in a customary manner adapted to the use forms.
5.45 g (20 mmol) of 3-(2,4,6-trimethylphenyl)-4-hydroxy-5,5-tetramethylene-xcex943-dihydrofuran-2-one (known from EP-A-0 528 156) are initially charged in 80 ml of dichloromethane, 3.04 g (30 mmol) of triethylamine are added and, at 0-10xc2x0 C., a solution of 3.50 g (26 mmol) of 3,3-dimethylbutyryl chloride in 20 ml of dichloro-methane is then added dropwise.
After 2 hours, a further 0.50 g (5 mmol) of triethylamine and 0.40 g (3 mmol) of acid chloride are added, and the mixture is stirred at room temperature for a further 16 hours.
For work-up, the mixture is washed twice with 10% strength citric acid and twice with 1N aqueous sodium hydroxide solution, and the organic phase is dried with sodium sulphate and concentrated.
Further purification of the crude product is effected by trituration with petroleum ether, filtration with suction and drying.
Yield: 4.50 g of a white solid (61% of theory) of melting point: 98xc2x0 C.